Recording spirometer



April 21, 1964 v J. NEMEC ETAL RECORDING SPIROMETER Filed Aug. 15, 1962 United States Patent O 3,129,705 RECQRDENG SPlRMETER Jaroslav Nmec, Kanice, and Jaroslav Jernnek and Old'ich Caha, Brno, Czechoslovakia, assignors to Presn mechanika, nrodny podnik, Stai-a Gura, Czechoslovakia Filed Aug. 15, 1962, Ser. No. 217,064 SClaims. (Cl. 12S-2.97)

The present invention relates to a spirometer apparatus for indicating and recording lung capacity and oxygen consumption. The lung capacity data obtained permit certain diseases to be discovered in their initial stages, such as chronic bronchitis, emphysema of the lungs, bronchial asthma, and silicosis. The determination of basal metabolism from the data on oxygen consumption is important in disorders of the thyroid gland.

Known devices for measuring basal metabolism generally comprise a downwardly open bell or cylinder filled with oxygen and floating on water which seals the opening of the bell. The bell is connected to inspiration and expiration tubes provided which check valves and terminating in the patients mouth, while his nose is kept closed. The patient inhales oxygen and exhales carbon dioxide through a vessel containing soda lime. The soda lime absorbs the carbon dioxide and the consumption of oxygen due to respiration causes a downward movement of the bell in the water seal. The bell is connected to a pen which records the movements of the bell on a rotating cylinder. The rate of basal metabolism can be derived from the record with the aid of suitable tables. The known instruments for recording lung capacity are based on the same principle, but are not equipped with a container of soda lime, and the bell is not filled with oxygen. The patient, having inhaled as much air as possible, exhales into the bell which thereupon moves upwards. This movement is registered as a curve from which a diagnosis can be determined.

All known instruments are equipped with two cylinders, i.e. an oxygen cylinder and a separate recording cylinder. The oxygen cylinder is usually made of relatively heavy metal, and is balanced by a counterweight to which it is connected by a rope trained over a roller. The cylinder and counterweight have undesirable inertia which unfavorably affects the recordings made. In general, the known instruments are designed for a range of measurements suitable for adult persons only and make it diicult to evaluate the lung capacity of children or of other persons of small lung capacity. Some of the known instruments are bulky, heavy, intricate, and expensive.

The general object of this invention is the provision of a spirometer which is free from the shortcomings of the known devices.

A more specific object is the provision of a spirometer which is simple in design, therefore inexpensive to manufacture, is light in weight, compact, and has a range of measurement wide enough to make it applicable both to adults and to children.

Other objects and many of the attendant advantages of this invention will become apparent as the disclosure proceeds.

The apparatus according to the invention will now be described with reference to the accompanying drawing which shows a preferred embodiment of the invention.

FIG. 1 shows a spirometer of the invention in an elevational, and generally sectional view on the line I-I in FIG. 2;

FIG. 2 shows the apparatus of FIG. 1 in a plan view; and

FIG. 3 shows a detail of the spirometer of FIG. 1 in plan section on the line III-III, drawn to enlarged scale.

The apparatus is mounted on a base plate 1 to which a cylindrical cover 2 is secured. A bearing 3 is arranged in the plate 1 coaxially with the cover 2. A disk 4 is mounted for rotation in said bearing. The disk 4 is provided with a peripheral cylindrical flange 4 whose inner face is selectively engaged by one of two friction rollers 5, 5 of different diameter. The rollers 5, 5 are driven by a gear motor 6. The motor 6 is pivotally mounted in a bearing 7 and can be swivelled by a lever 7 for selecting the speed of rotation of the disk 4 by the engaged roller. The two speeds of rotation of the disk 4 correspond to a peripheral speed of a recording cylinder 29 of 1 millimeter per second and 50 millimeters per second, respectively. The disk 4 is xed to a coaxial shaft 8 which is provided with a groove 8' extending over a substantial portion of its length. Two radially spaced cylindrical tubes 1i), 10 coaxial with the shaft 8 extend upward from the cover 2 and are integral therewith. They define two coaxial annular spaces about the shaft 8, and guide axial movement of a bell 22. The cylindrical outer wall of the bell is formed by the aforementioned recording cylinder 20. The bell is downwardly open and upwardly closed by fixed lid 23. A double walled tube 9 centrally fastened to the lid 23 slidably receives the shaft 8, and the bell is secured against rotation relative to the shaft by a key 24 fixed to the tube 9 and axially slidable in the groove 8.

Tubular walls 9a, 9b secured to the lid 23 movably receive therebetween the stationary tube 10. The outer cylindrical face of the tube 9 and the tubular wall 9a deline therebetween an annular chamber 18. The tubular wall 9b defines another annular chamber 19 with a tubular wall 9c inwardly adjacent the stationary tube 10. The tube 9, the tubular walls 9a, 9b, 9c, and the lid 23 are integral and coaxial about the axis of the shaft 8. The bell 22 is made of a unitary piece of light plastic such as polyethylene.

The tubes 10, 10 form a container C, and the space between these tubes, above the cover 2, is partly lled with Water which also enters the downwardly open chamber 19, as shown at 25. The bell 22 is provided with airlilled floats 11 in the chamber 19 which make the entire bell structure buoyant on the water 25. Two tubes 21 communicating with openings in the lid 23 connect the chambers 18, 19.

A bracket 15 mounted on the base plate 1 supports a mouthpiece assembly which includes an inhalation pipe 13 and an exhalation pipe 13. The pipes pass upward through the cover 2 into circumferentially juxtaposed portions of the chamber 18. The inhalation pipe 13, not seen in FIG. 1, has an open end in the chamber. A perforated container 12 holding soda lime is fastened over the open end of the pipe 13 by a rubber sleeve 12. The ends of the tubes 13, 13 outside the bell 22 are connected to a mouthpiece 14 which is valved in a manner conventional in this art to respectively open the pipes 13, 13 when a person inhales and exhales through the mouthpiece.

A vertically arranged slender rod 16 is secured at its lower end to the cover 2 by means of a screw clamp 16. The upper end of the rod 16 supports a sleeve 17 in such a manner that the weight of the sleeve tends to urge the same toward the recording cylinder 20. A pen 17 mounted on the sleeve 17 is thereby held in contact with the surface of the cylinder 20 or with a sheet of recording medium (not shown) which may be mounted on the cylinder 20 in a conventional manner.

The apparatus according to the invention admits of universal application and is suited for the determination of basal metabolism as well as of lung capacity in children and in adults.

When employed for investigating metabolism, the apparatus is operated as follows:

A recording sheet is fixed on the recording cylinder 2?. An oxygen bottle is connected to the mouthpiece 14, and the bell 22 is lled with oxygen so that it rises to its uppermost position. The patient breathes into the mouthpiece and the bell 22 performs a twofold movement. Due to the patients breathing, it rises and sinks, sliding up and down along the grooved shaft 8. Simultaneously, it is rotated by the shaft in one direction at a peripheral speed of 1 millimeter per second. The pen 17 is in contact with the recording sheet on the cylinder 20 and records a spirogram.

The investigation of lung capaciity is performed as follows: A recording sheet is fitted on the cylinder 2t), While the same is in its lowest position and set for rotation at a circumferential speed of 50 millimeters per second. The patient draws in air and then exhales briskly into the mouthpiece. The bell 22 carrying the recording sheet rotates and rises at the same time. The pen 17 records a graph characteristic of the vital capacity of the lungs.

When the apparatus is used with adults, the chambers 1S and 19 are connected by the tubes 21. For testing children and other persons of low Vita capacity, the chamber 19 is sealed from the chamber 18.

What we claim is:

l. A recording spirometer comprising, in combination:

(a) a container adapted to hold a liquid therein;

(b) a bell mounted in said container for rotation about a fixed longitudinal axis, said bell being axially movable in said container while floating on said liquid, and deiining a cavity therein arranged for communication with said liquid;

(c) means on said bell deiining a cylindrical surface about said axis;

(d) drive means for rotating said bell about said axis at a predetermined speed;

(e) a pen secured to said container for recording contact with a recording medium on said cylindrical surface; and

(f) mouthpiece means cavity.

2. A recording spirometer comprising, in combination:

(a) a container adapted to hold a liquid therein;

(b) a downwardly open bell mounted in said container for rotation about a fixed, vertically extending axis, said bell being axially movable in said container;

(c) means on said bell defining a supporting surface for a recording medium cylindrically curved about said axis;

(d) drive means for rotating said bell about said axis at a predetermined speed;

(e) a pen secured against rotation relative to said container and arranged for recording Contact with said recording medium; and

(f) mouthpiece means including a tubular member terminating in said container within said bell.

3. A recording spirometer as set forth in claim 2, furcommunicating with said ther comprising wall means in said bell defining two downwardly open chambers in said bell; and a conduit connecting said chambers, said conduit extending outside said bell, one of said chambers being annular about said axis, said tubular member being secured to said container against rotation about said axis and terminating in said annular chamber.

4. A recording spirometer as set forth in claim 3, wherein said mouthpiece means include a second tubular member secured to said container against rotation and terminating in said annular chamber, and carbon-dioxide absorbing means on one of said tubular members in said annular chamber.

5. A recording spirometer comprising, in combination:

(a) a support;

(b) an annular container mounted on said support and adapted to hold a liquid, said container having a lvertically extending axis;

(c) a downwardly open bell mounted on said support Lfor rotation about said axis and free to move axially while rotating;

(d) coaxial cylindrical wall means on said bell deiining two annular, downwardly open chambers in the same, one of said chambers being movably received in said annular container, and the other chamber being outside said container;

(e) means on said bell defining a cylindrical recording surface about said axis;

(f) drive means for rotating said bell about said axis at a predetermined speed;

(g) a pen secured on said support against rotation about said axis, and arranged for recording contact with said recording surface while said -bell is rotated about said axis; and

(h) mouthpiece means including at least one tubular member mounted on said support and terminating in said other chamber.

6. A recording spirometer as set forth in claim 5, wherein said drive means include a motor, and dual-speed motion transmitting means interposed between said motor and said bell for selectively rotating said lbell at two different speeds when said motor operates.

7. A recording spirometer as set forth in claim 5, further comprising a conduit connecting said air chambers.

8. A recording spirometer as set forth in claim 5, further comprising a float arranged on said bell for engagement with a liquid in said container.

References Cited in the tile of this patent UNITED STATES PATENTS 952,307 Childs Mar. 15, 1910 2,527,716 Fleisch Oct. 3l, 1950 FOREIGN PATENTS `620,502 France Jan. 2l, 1927 1,252,549 France Dec. 19, 1960 

1. A RECORDING SPIROMETER COMPRISING, IN COMBINATION: (A) A CONTAINER ADAPTED TO HOLD A LIQUID THEREIN; (B) A BELL MOUNTED IN SAID CONTAINER FOR ROTATION ABOUT A FIXED LONGITUDINAL AXIS, SAID BELL BEING AXIALLY MOVABLE IN SAID CONTAINER WHILE FLOATING ON SAID LIQUID, AND DEFINING A CAVITY THEREIN ARRANGED FOR COMMUNICATION WITH SAID LIQUID; (C) MEANS ON SAID BELL DEFINING A CYLINDRICAL SURFACE ABOUT SAID AXIS; (D) DRIVE MEANS FOR ROTATING SAID BELL ABOUT SAID AXIS AT A PREDETERMINED SPEED; (E) A PEN SECURED TO SAID CONTAINER FOR RECORDING CONTACT WITH A RECORDING MEDIUM ON SAID CYLINDRICAL SURFACE; AND (F) MOUTHPIECE MEANS COMMUNICATING WITH SAID CAVITY. 